H. A. Phillips & Co. of Chicago, Illinois, assignee of this application, has long been a leader in the design, development and installation of industrial refrigeration systems. A pioneer in recirculating systems, its engineers have constantly sought new and improved refrigeration systems and equipment of this type. Systems and components for refrigeration which have been developed at Phillips include those covered by Phillips U.S. Pat. No. 2,570,979; Phillips U.S. Pat. No. 2,589,859; Phillips U.S Pat. No. 2,641,281; Richards U.S. Pat. No. 2,841,962; Richards et al. U.S. Pat. No. 2,871,673; and Ross U.S Pat. No. 2,966,043.
These systems, as well as others in the prior art, provided excellent operational results in terms of refrigeration through both winter and summer, nightime and daytime operation. However, wide variations in ambient temperature do effect the efficiency of most known systems in an undesirable manner. Higher power usage and costs are the normal result.